EYE ALLERGIES AND GLAUCOMA

Ophthalmologist Carolina Valdivia, MD discusses eye allergies and glaucoma, and if pollen can cause increased eye pressure.

Hello Dr. Valdivia. I am a glaucoma patient. Medications that I take include Xalatan, Timolol and Azopt. I would like to know if pollen causes increased eye pressure. My vision is so blurry during this time of year. Your insight on this issue will be greatly appreciated.



Thank you for your question and your interest in glaucoma-eye-info.com.

Judging from your question, it appears that you are experiencing problems with seasonal eye allergies.

Let me first allay your concerns. Airborne allergens such as pollen do not cause elevations in intraocular pressure. It might seem this way because they cause allergy eye symptoms that are superficial, such as watering and redness. But these problems do not extend to the internal structures of the eye and therefore are not connected to your glaucoma. Simply stated, there is no direct connection between seasonal eye allergies and glaucoma.

Allergies are disorders of the immune system. They represent a form of hypersensitivity to usually harmless environmental substances known as allergens.

Airborne allergens cause conditions, such as hay fever and allergic conjunctivitis (eye redness and excessive tears), which are highly prevalent across the world. Other common or associated allergy eye symptoms are itchiness, runny nose, and a feeling of pressure around the eyes.

The feeling of puffiness around the eyes sometimes leads patients to believe that they have increased eye pressure. However, this is not true. Instead, it is due to inflammation of mucus membranes in the eyes and nasal cavity. Again, there is no direct connection between seasonal eye allergies and glaucoma.

The reason that people often experience allergy eye symptoms is because airborne allergens (foreign substances) cause an inflammatory reaction in the conjunctiva, a membrane that covers the white part (sclera) of the eye. Normally the conjunctiva is transparent. However, during an allergic reaction, a substance called histamine causes blood vessels in the area of the conjunctiva to dilate in order to allow agents of the immune system to enter, such as white blood cells and other proteins. These then engage the foreign substance in an attempt to remove it.

The dilated vessels cause eye redness. They also permit fluids from the blood to exit, which leads to tearing and a runny nose. At the same time, the conjunctiva begins to swell as part of the inflammatory process and its glands over-secrete mucus. This also contributes to excessive tearing and can result in blurred vision. Histamine, in turn, stimulates certain nerve receptors and makes the eyes itch and causes sneezing. Taken together, these factors lead to a feeling of increased eye pressure.

As you can see, inflammation caused by airborne allergens has no connection to the factors that lead to elevated intraocular pressure that I discuss elsewhere on glaucoma-eye-info.com. They are two distinct problems.

Some people with allergies visit my office that also show signs of glaucoma, such as increased eye pressure. In these cases, allergies can be the precipitating event that resulted in their visit to me, but still are not the cause of the glaucoma symptoms. The actual cause is that people suffering from seasonal eye allergies oftentimes self-diagnose the problem and treat themselves with various medications that contain steroids. The overuse of steroidal preparations can lead to a condition called drug-induced glaucoma.

It is important that you report any medications (prescription or over-the-counter) that you are taking to control your allergies to your ophthalmologist. Your general physician also should be made aware that you are taking medications for glaucoma.

In some cases, your ophthalmologist or general physician may prescribe a steroid-containing medication. If this is the case, make sure that you take it only for the period that it has been prescribed and report any problems with your vision while taking the medicine immediately.

I hope that this clears up any misconceptions that you might have had about eye allergies and glaucoma. Feel free to write again if you have other questions.

Carolina Valdivia, MD

REFERENCE:

Cruse JM and Lewis RE. Atlas of Immunology, 2nd Ed. Boca Raton, Florida: CRC Press, 2004:347-377.

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